Apparatus and method for freeing well pipe



March 17, 1970 D. s. BARLER 3,500,908

APPARATUS AND METHOD FOR FREEING WELL PIPE Filed NOV. 14, 1967 2Sheets-Sheet 1 INVENTOR.

\Q Dew/v/s .5. B/QIQL 2 ATTORNEY March 17, 1970 u. s. BARLER 3,500,908

APPARATUS AND METHOD FOR FREEING WELL PIPE Filed Nov. 14, 1967 2Sheets-Sheet 2 KEZEli A V EE -i 4 F l G 7 DEN/W376. BHRLEE ATTORNEYUnited States Patent 3,500,908 APPARATUS AND METHOD FOR FREEING WELLPIPE Dennis S. Barler, 12031 Blackmer, Garden Grove, Calif. 92641 FiledNov. 14, 1967, Ser. No. 683,395 Int. Cl. E21b 23/00 US. Cl. 166--77.5 3Claims ABSTRACT OF THE DISCLOSURE An apparatus including a number ofrotatable powerdriven eccentrics which are connected to an elongatemember such as a drill pipe that is stuck in an oil well bore hole, andto a resiliently movable support suspended from the traveling block onan oil derrick. When the power-driven eccentrics are operated, theelongate member is subjected to vertically directed forces to free itfrom the stuck position.

BACKGROUND OF THE INVENTION Field of the invention Apparatus and methodof using same to free an elongate, rigid member which has become stuckin an oil well bore.

Description of the prior art In the drilling of an oil well, a drillstring may become stuck in a bore hole at a location that may range froma position adjacent the bit to a position intermediate the bit and theground surface. Heretofore, the prevailing practice for freeing suchstuck pipe has been to use special crews employing an overshot reamerand wash pipe to remove the earth formation surrounding the stuck pipeportion. Such an operation is time-consuming and expensive, and by nomeans assures total freeing and freeing of the entire string from thebore hole.

The purpose of the present invention is to provide an apparatus andmethod of using same by which pulsed, longitudinally directed forces areexerted on the stuck drill string to free the same, which operation isadapted to be carried out by a regular drilling crew at a relatively lowcost, in contrast to the expensive, time-consuming methods previouslyavailable for achieving the same result.

SUMMARY OF THE INVENTION An apparatus in which at least one horizontallydisposed pair of heavy, eccentrically loaded, synchronously drivenbodies are rotated in a rigidly coupled condition relative to a stuckdrill pipe to impart pulsed, longitudinally directed forces thereto andfree said pipe in an oil well bore.

A major object of the present invention is to provide a power drivenpiece of equipment that may be supported from a traveling block, which,when rigidly coupled to a stuck drill pipe may be employed to free thelatter.

Another object of the invention is to provide an apparatus that issimple and easy to use, may be operated by a regular drilling crew, andwhich minimizes the costs and inconvenience encountered in the use ofpreviously available equipment used for such purpose.

A still further object of the invention is to furnish a method offreeing a stuck elongate member located in an oil well bore hole thatovercomes the operational disadvantages of prior apparatus and methodsused for this purpose.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a side elevational View ofthe poweroperated vibrating unit removably supported from a travelingblock which is rigidly coupled to a stuck drill string;

FIGURE 2 is an enlarged end elevational view of the apparatus;

FIGURE 3 is an enlarged side elevational view of the apparatus;

FIGURE 4 is a perspective view of one of the spring assemblies used insaid apparatus;

FIGURE 5 is a fragmentary, vertical, cross-sectional view of the unit,taken on the line 5--5 of FIGURE 3;

FIGURE 6 is a fragmentary, vertical, cross-sectional view of theapparatus, taken on the line 6-6 of FIG- URE 2; and

FIGURE 7 is a top plan view of the unit, taken on the line 7-7 of FIGURE6.

DESCRIPTION OF THE PREFERRED EMBODIMENT The oil well tubular memberfreeing apparatus A, as can best be seen in FIGURES 1 to 3, includes asupport B that can be removably affixed to a traveling block C to holdan upper rigid frame D at a desired elevation above a rotary table E ofan oil well F. An elongate, rigid mem ber G, such as a string of drillpipe, or the like, is stuck in well F. Member G projects upwardly aboverotary table B.

One or more spring assemblies H depend from upper frame D, each of whichassemblies resiliently support a lower frame I. In FIGURE 2, applicantsapparatus is illustrated as having three spring assemblies H. However,it is possible to use either more or less of these Spring assemblies H,and still provide an operative apparatus A.

A heavy, rectangular, closed frame K depends from lower frame I whichserves as a support for one or more pairs of heavy, power-driven,eccentrically loaded, rotatable bodies L. The bodies L are connected bygears M in such a manner that the eccentrically loaded portions thereofreach their uppermost and lowermost positions in unison. When the bodiesL are rotated in unison, the frame K tends to reciprocate upwardly anddownwardly. The frequency at which frame K reciprocates upwardly anddownwardly is, of course, determined by the speed at which the bodies Lrotate.

An internally threaded socket N is rigidly secured to the lower portionof frame K. Socket N is threadedly engaged by an elongate rigidconnector 0 that rotatably supports an internally threaded cup P on anenlarged lower end thereof; as shown in FIGURE 5. Cup P engages theupper threaded end of a heavy tubular inverted Y-shaped fitting Q, whichfitting Q, as may best be seen in FIGURE 2, is threadedly connected tothe upper end of the elongate member G, normally a string of drill pipe,that is stuck in oil well F.

A flexible hose -R extends from a mud pump (not shown) to a tubular leg10 of fitting Q. The upper end 12 of leg 14 of fitting Q is sealed, inthe manner shown in FIGURE 5, whereby mud pumped into the fitting Q iscaused to flow downwardly through a leg 16 thereof into the member G.When mud enters the member G it passes downwardly therein to dischargethrough a bit (not shown) connected to the lower end of the elongate 3iember. Thereafter, the mud passes upwardly through 11 annulus-shapedspace 18 (FIGURE 1) defined beween the elongate member G and bore holeof oil well F 3 act as a lubricant.

Traveling block C is caused to move upwardly to place n upwardlydirected force on the member G. Rotatable odies L are then caused torotate in unison by means to e explained, and due to the eccentricloading of these odies, the lower frame I, frame K, connector 0, andfiting Q tend to reciprocate upwardly and downwardly to npart spacedpulses of upwardly and downwardly diected forces to the stuck elongatemember G. These lulsed oppositely directed forces, in combination withthe ubricating action of the mud flowing around the stuck rortion ofmember G, will gradually work the stuck porion of the member loose andpermit it to be retrieved mm the well. The frequency of the pulses offorce on he member G is controlled by varying the rate at which heeccentrically loaded bodies L rotate.

In detail, the support B comprises an elongate rigid )ody 20, the upperend of which is so shaped as to renovably receive a hook 22 that forms apart of the raveling block C. A downwardly extending recess 24 3 formedin the lower end of body 22 and removably eceives an invertedmilk-bottle-shaped, rigid member 26 hat extends upwardly from the centerof upper frame D. rame D (FIGURE 2) includes two rigid arms 28 whichlepend downwardly and outwardly in opposing directions rom body 26, andthe outer extremities of these arms ire joined by a rigid crosspiece 30.A number of longiudinally spaced clevises 32 depend from crosspiece 30,md a number of reinforcing members 31 extend between he arms 28 andcrosspiece, as may also be seen in FIG- JRE 2.

By means of a pin 34, each of the clevises 32 is secured o a lug 36projecting upwardly from a first plate 38 'orming a part of one of thespring assemblies H. Each tssembly H also includes second and thirdplates 40 and I2 that are in spaced relationship situated below first)late 38. The second and third plates 40 and 42 of each ipring assemblyH are connected by a number of cylinlrical shells 44, as illustrated inFIGURE 4.

A piston 46 is slidably mounted in each shell 44, and :ach piston 46 isconnected to the lower end of the shank 18 of a bolt 50 provided with ahead 52. The shanks 48 :xtend through pairs of vertically aligned bores54 Formed in the first end second plates 38 and 40 respec- ;ively, asshown in FIGURE 4, A heavy coiled spring 56 is disposed in each shell44, with the lower end of :his spring resting on one of the pistons 46and the upper and of the spring abutting against the lower surfaceof meof the second plates 40.

Lugs 58 extend downwardly from the third plates 42, and by pins 60 theselugs are connected to clevises 62 :hat project upwardly from a crossbar64 forming a part of lower frame I. The frame I also includes two arms56 that extend downwardly and inwardly towards one another from theouter extremities of crossbar 64 and merge at a junction 68. A number ofreinforcing members 67 extend between arms 66 and crossbar 64.

Frame K (FIGURE 3) includes two parallel, laterally spaced side pieces70', a bottom piece 72 and top piece 74. A bolt 76 extends through atransverse bore 78 in junction 68 to engage a clevis 80 located at thecenter of top piece 74 that is preferably formed as an integral partthereof, all of which may be seen in FIGURE 3.

Bottom piece 72 supports horizontal rectangular, rigid housings 84, 86,88 and 90, open at the top and bottom, which are stacked one upon theother within the confines of frame K, with the lowermost housing 90resting on platform 82. Apertured lugs 84a, 86a, 88a and 90a extendoutwardly from housings 84, 86, 88 and 90, as also shown in FIGURE 3.

Four rods 92 are provided, the upper and lower ends of which arethreaded. The rods (FIGURE 3) pass 4 through lugs 84a, 86a, 88a and aand bores 82a. Nuts 94 engage the threaded ends of rods 92 to clamp thehousings 84, 86, 88 and 90 together and secure the housings as anintegral unit to the platform 82.

In abutting edges of the housings 84, 86, 88 and 90, transverselyaligned semi-circular recesses 84b, 86b, 88b and 90 are formed that gripshafts 95 (FIGURE 3) of squirrel cage type motors having stators whichrotate rela tive to the shafts, which stators comprise the bodies L.Portions of the bodies L are removed resulting in eccentrically loadedportions 96 of the bodies, as shown in FIGURE 6. The bodies L receiveelectrical energy from cables 97 by conventional means (not shown). Thegears M are rigidly secured to bodies L, and these gears mesh in themanner illustrated in FIGURE 6. Bodies L rotate in the directionsindicated by the arrows 98 in FIGURE 6.

Due to the gears M, the bodies L must rotate at the same speed and inunison, with the eccentric loadings 96 reaching their innermost andoutermost positions at the same time, and in so doing, cancelling outsidewise thrusts resulting from the rotation of the individual bodies.The eccentric loadings 96 all reach their uppermost and lowermostpositions in unison, thereby developing intermittently spaced pulses ofupwardly and downwardly directed forces which are imparted to the rigidmember G to shake it loose from its stuck position as described herein.The pulses of upwardly and downwardly directed forces so developed causethe plates 40 and 42 and shells 44 to reciprocate vertically relative tothe springs 56 and pistons 46, as well as the lower frame I, but with noreciprocating movement being transmitted to the upper frame D.

During the time the eccentrically loaded bodies L are caused to rotate,mud is pumped downwardly through the stuck member G as described, tolubricate the stuck portion of the member and facilitate freeingthereof. Threads 100 are formed on the lower exterior surface of leg 16which threadedly engage a tapped upper end 102 of elongate tubularmember G, as best seen in FIGURE 3.

What is claimed is:

1. In combination with a tubular member stuck within an oil well, whichmember has a threaded upper end, an apparatus for freeing said member,including:

(a) upper and lower rigid frames;

(b) resilient means for supporting said lower frame from said upperframe, which means includes:

(1) a first horizontal plate supported from said upper frame andsituated therebelow,

(2) second and third vertically spaced, horizontal plates positionedbelow said first plate and in vertical alignment therewith,

(3) a plurality of parallel cylindrical shells extending between saidsecond and third plates and rigidly secured thereto, with the interiorof said shells being in communication with a plurality of vertical boresformed in said second plate, which bores are smaller in transverse crosssection of said shells,

(4) a plurality of pistons slidably mounted in said shells,

(5) a plurality of shanks depending from said first plate and extendingthrough said bores in said second plate, with the lower ends of saidshanks being secured to said pistons,

(6) a plurality of helical springs disposed between said pistons andsaid second plate within said shells, and

(7) means for securing said third plate to said lower frame;

(c) first means for adjustably supporting said upper frame at a desiredelevation above said well;

(d) at least one pair of heavy, eccentrically loaded, power-drivenbodies that are transversely spaced a fixed distance in a horizontalplane and rotate in opposite directions, with the eccentric loading onsaid bodies being so predetermined that said bodies alternately exert anupward and downward force only, during rotation thereof;

(e) rigid frame means for supporting said powerdriven bodies;

(f) second means for connecting said frame means to said lower frame;and

(g) third means for rigidly connecting frame means to said upperthreaded end of said tubular member, with said tubular member beingalternately subjected to upwardly and downwardly directed forces as saideccentrically loaded bodies rotate to free said tubular member from saidstuck position.

2. An apparatus as defined in claim 1 wherein said eccentrically loaded,power-driven bodies comprise portions of electric motors.

3. An apparatus as defined in claim 1 wherein said eccentrically loadedpower-driven bodies comprise stators of electric motors that rotateabout shafts forming parts of said motors, which apparatus furtherincludes:

(h) means for holding said shafts in fixed stationary positions in saidframe means.

References Cited UNITED STATES PATENTS 15 ERNEST R. PURSER, PrimaryExaminer US. Cl. X.R.

